Typically, automotive vehicles include a frame, also referred to as a chassis, which provides the primary structural support for the vehicle. Contemporary styling and good aerodynamic practice in truck design make use of chassis skirts which cover the lower portions of the truck chassis. Prior art chassis skirts are attached to a framework which depends from the vehicle chassis with bolts. A disadvantage of these chassis skirts is that access to some components which are mounted on the frame rails or on supports depending from the frame rails of the vehicle chassis is obstructed by the chassis skirt. Inspection or repair of these components can require removal of the chassis skirt, and can require a technician to crawl under the truck to make adjustments.
Another type of known chassis skirts are tank-mounted skirts. While tank-mounted skirts reduce the cost and weight associated with a chassis skirt, tank mounted skirts introduce much larger tolerance stack-ups into the assembly. Adjustments on the tank-mounted skirts are very cumbersome and can take hours to complete. Often, if the chassis skirt and tank assemblies are assembled correctly, one of the other components on the truck, such as the frame rails or cab, would be misaligned enough to cause the skirts to rub on the hood or on each other.
Prior art chassis skirts are only adjustable radially (both vertically and horizontally dependently together) around the fuel tanks. Since there is limited room between the tanks, steps and chassis skirts, it was not believed that adjustment in three axes could be provided. Since radial adjustment causes the skirts to be adjusted both vertically and horizontally at the same time, a desired vertical alignment may be obtained, but in doing so, the horizontal alignment (cross-car) might become misaligned, or vice versa. The result is chassis skirts that are not properly aligned.